The present invention relates to an improved method and apparatus for treating coolant for an internal combustion engine.
Presently, internal combustion engines utilize a closed coolant system for cooling the internal combustion engine wherein the engine block is cooled by a liquid coolant. The coolant is in turn pumped to a radiator, which is a heat exchanger, to cool the liquid coolant which is then returned to the engine block. It is common to utilize the coolant to provide heat to a passenger compartment of a motor vehicle wherein the heater is an auxiliary heat exchanger for cooling the coolant and simultaneously deliver heat to the passenger compartment.
A well accepted coolant which is used in many cooling systems is a formulation which is primarily ethylene glycol. Ethylene glycol is popular because it is efficient in carrying heat, and it has a low freezing point so that it will not freeze readily in cold weather.
Ethylene glycol coolant has a high boiling point and is also usable in the summertime. The ethylene glycol coolant then may be utilized in an internal combustion engine the year around. Typically, coolants which have ethylene glycol as their base contain various additives, such as, rust inhibitors, which prevent rust from building up in the cooling system. With the passage of time, the rust inhibitors tend to be used up and must be replenished.
Many service stations advise their customers that they should drain the coolant prior to a winter season and replace it with a fresh supply of coolant which contains all of the additives. The service stations disposed of ethylene glycol by dumping it into a municipal sewage system. However, the ethylene glycol has been found to be a pollutant and municipal sewage systems prohibit the dumping of ethylene glycol into the sewage system. Thus, the service stations can no longer discard the ethylene glycol quickly and conveniently in a municipal sewage system, and therefore, no longer advise their customers to change the coolant but rather suggest the addition of additives, such as, rust inhibitor, and replenishment of any lost ethylene glycol.
The utilization of an apparatus and method for testing, filling and purging closed fluid systems is taught in U. S. Pat. No. 4,782,689, issued May 8, 1988, Raymond D. DeRome. An engine coolant flush-filtering, using external gas pressure is taught in U.S. Pat. No. 4,793,403 issued Dec. 27, 1988, to Vataru et al., and a radiator construction is taught in U.S. Pat. No. 1,554,924, issued Sept. 22, 1925, to Shapiro.